Rear fog light brake conversion problem

[ax53]

So I recently did an attempt at the "skyline" brake light mod where the rear fog lights are converted into brake lights. So I got myself an extra pair of brake light bulb holders for the fog lights, and then I soldered them in, in parallel with the normal brake lights. Kinda like this:

 

The problem is that on the left side. The fog-brakelight stops working after 1 second. The fog-taillight keeps working, and the normal brake light keeps working. So it's not a short, it's not a bad ground, it's also not a burnt bulb. Which leaves me scratching my head, what the heck could it be? Could it be something strange like too much current because the ground is too good? Or is it just a bad wire? If anyone has any tips on what it could be it would be greatly appreciated. Thanks.

[Herbie]

Faulty bulb? Switch bulbs round and see if the fault moves to the right side and also see if the bulb now in the left exhibits the same symptoms.

Bulb not secure in holder? Bulb holder faulty?

[ax53]

On 6/28/2019 at 6:50 PM, Herbie said:

Faulty bulb? Switch bulbs round and see if the fault moves to the right side and also see if the bulb now in the left exhibits the same symptoms.

Bulb not secure in holder? Bulb holder faulty?

Ah yes i forgot to mention the problem stays on the left when I switch the bulbs around. It could be the holder. I have to check. Thanks.